Underwater lamp



June 17, 1958 v K. H. WILCOXON v2,839,673

UNDERWATER LAMP Filed April 30, l 956 3 Sheets-Sheet 1 ATTORNEY$ June 17,1958 Q K. H.wn.coxoN UNDERWATER LAMP 3 Sheets-Sheet 2 Filed April -30, 1956 INVENTQR v I M0104 '\z- 4 g BY 4. 2%,... ATTORNEY$ June 17, 1958 K. H. WILCOXON UNDERWATER LAMP 3 Sheets-Sheet 3 Filed April 30, 1956 INVENTOR jfemzeififwkdzdig BY a y 4 r' r ATTORNEYS UNDERWATER LAMP Kenneth H. Wilcoxon, Cabin John, Md., assignor to the United States of America as represented by the Secretnry of the Navy Application April 30, 1956, Serial No. 581,813

' 8 Claims. ((31. 240-26) (Granted under Title 35, U. S. Code (1952), sec. 266) cation is a continuation-in-part of application Serial No.

545,809, filed November 8, 1955, and now abandoned.

This invention relates to high-intensity light units; and

more particularly relates to a high-intensity light unit for underwater use, especially in salt sea water.

An object of the invention is to provide an underwater light unit adapted to carry a high intensity lamp or bulb that will give enough light for television and other purposes.

Another object of the invention is to provide an underwater light unit having a reflectorprotected against corrosion by contact with ambient water.

A further object is to provide an underwater light unit having means for cooling the lamp or" bulb contained therein with the ambient or surrounding water without detrimental effects on other parts of the unit, such as, for example, the reflector and the electrical connections to the bulb. V p f Another object of the present invention is to provide a lamp unit of a type described whereby the bulb can be easily replaced, and without disturbing the protection of the reflector of the unit against contact with-the surrounding water.

Still another object of the invention is to provide an underwater light unit with a novel joint or connection Wires to the light bulb in such a manner as to protect the metal parts against the corrosive action'of'sa'lt water and/or high temperature.

In general, a light unit in accordance with the invention comprises an opaque reflector block having a cavity formed therein to provide a reflecting surface. A lens or cover-plate is watertightly secured over the front of the cavity. The reflector block has a throughhole at its rear which passes through the rear of the reflector cavity and watertightlyreceives atube in whichthe highintensity light bulb is supported. The intensity of the preferred bulb is so great that the bulb operates at a tem perature that easily converts water-intosteam. Water circulates through the tube for cooling the bulb and surrounding parts. The bulb is of the elongated type having connection-terminals at its ends, and an improved connection joint is made thereto to'protect the electricityconducting metallic parts against corrosion and otherde terioration by the proximate water. The tube and lens or cover plate through which the light from the bulb'shines are of a light-pervious'material, using the term light pervious as embracing both transparent and translucent.

Other features and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: p f r Fig. 1 is a vertical sectional view of alight unit in accordance with the invention;

States Pa ent P 2,839,673 Patented June 17, 1958 ICC Fig. 2 is a horizontal sectional view taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is a front view, substantially to scale, of the reflector block of the lamp unit;

Figs. 4 and 5 are sectional views, substantially to scale of the reflector block taken substantially on the lines 4-4 and 55, respectively, of Fig. 3; and

shown, a protective cover plate or lens 9 at the front of reflector block 5, a light-pervious tube 11 extending vertically through the reflector block at the rear thereof, an elongatedlight bulb 13 inside the tube 11, and wires 15 and 17 -connected respectively to the terminals of the bulb 13. Any suitable expedient may be used to position or hold the bulb 13 inside the tube 11.

In the preferred embodiment, the reflector block 5 is an aluminum casting .cast with a reflector cavity. The outer surfaces of the block are machined smooth and the reflector cavity is further polished directly. or after a.

nickel or other plating to provide the reflector surface 7.. The block 5 also comprises an oval front edge 23 and a back face 25 of the same outside dimensions. A plurality of spaced threaded holes 27 are machined into the front portion of the block. A hole or bore 29 is machined through the block 5 atxits rear, the hole 29 extending vertically parallel to the long axis of the reflector surface I and intersecting the rear of the surface along the out line 31 shown in Fig. 3. The hole 29 may be considered to comprise an upper bore portion and lower bore portion as viewed in Figs. 1 and 3.

The hole 29 receives the light-pervious tube 11 which is of a heat-resistant glass, such as for example, pyrex." The tube 11 has an outer diameter slightly less than the diameter of the hole 29 so as to allow for relative thermal expansion between the tube and the metal block 5.

Suitable seals are provided that hold the tube 11 in the hole 29, and water-tightly seal the tube in the hole. To this end, upper and lower bore portions of the hole 29 are provided with annular recesses 35 and 33, respectively, which receive resilient, gasket-type O-rings 37.

The tube 11 receives the light bulb or lamp 13. The

bulb may be, for example, of the mercury vapor type. For a light unit with a reflector block having a maximum dimension of 6% inches (the vertical distance in Fig. 3) a bulb was used of the EH6 type made by General Electric and having a rating of 1000' volts and 1 ampere. or 1 kilowatt. This bulb provides a highly concentrated light of about 65,000 lumens and may operate at temperatures in the order of 1500 F.

In accordance with an. aspect of the invention, the terminals of the bulb 13 are-connected to the wires 15 and 17 in the manner shown in Fig. 6.

With reference to Fig. 6, the bulb 13 comprises a glass envelope .39 to each end of which a cylindrical metal terminal 41 is gastightly sealed, the outer diameter of the terminal being'smaller than that of the envelope 39.

One of the wires, 15 or 17 as the case may be, is detachably connected to the associated terminal 41 by means of a cylindrical brass connector 43.

Each wire comprises a central conductor 45 wrapped or surrounded by insulation embrasive'ly' indicated by the reference numeral 47 for withstanding the operating volt:

Serial No. 545,809.

in a suitable hole in one end of the connector 43. The other end of the connector 43 is provided with a hole defined by a wall 51 that detachably fits over the terminal 41. Preferably the wall 51 has two or more spaced narrow slots that extend axially of the connector to the bottom of the hole therein for the terminal, so as to provide a frictional press fit in a well-known manner. The outer diameter of connector 43 is less than that of the portion of the envelope 39 at the terminal.

Before the connector is engaged with the associated terminal, a snug-fitting temperature-resistant silicone rubber sleeve 53 is slipped or otherwise placed thereover with the end 55 of the sleeve extending slightly but sufficiently beyond the connector 43 so that the sleeve will contact and press against the envelope 39 to provide a substantiallywatertight seal or joint that prevents water from reaching the conducting metal of the joint. Preferably the connector 43 has an outer diameter that corresponds to that of the associated conductor 15 or 17;

and, as shown in Fig. 1, so that the sleeve 53 fits over both, and preferably extends beyond the block 5.

The front end of the lamp unit 3 is watertightly closed by the flat coverplate or lens 9 of a light-pervious plastic such as for example Incite. Screws 57 in threaded holes 27 secure the lens 9 to the edge 23 of the block 5. A rubber gasket 59 is interposed between the lens and block. 7

It is advantageous to fill the reflector cavity with clear clean water. To this end, the forward part of the block is provided with a suitable hole 61 that extends to the reflector cavity and can be closed tightly by a removable pipe plug 63, as shown in Fig. 1. The reflector cavity can be filled with clear fresh water through hole 61.

By completely filling the cavity with clean clear water, a means is provided for offsetting the external water pressure on the outer face of lens 9 when the light unit is submerged in deep water. The clean water in the reflector also protects the reflector surface against corrosive action and helps to keep'the unit cool.

The bulb 13 may be held in place by wrapping the wires 15 and 17 around the reflector block, a supporting bracket or clamp for the lamp unit. The wires 15 and 17 are usually adequate for such purpose and by simple inspection and manual adjustment the bulb 13 can be placed centrally in the tube 11 which, for practical purposes, is close enough to the focal points of the reflector surface along its long'axis. The tube 11 is otherwise unobstructed in the preferred embodiment.

Obviously, if desired, a more elaborate means can be used to hold the bulb and connecting wires in place; such as for example that shown in the aforesaid application If desired, one or more spider-like spacers can be attached to the wires to help center the bulb in tube 11, the spiders being located between the bulb and outer surface of the lamp unit. a a

It is preferred that the lamp unit 13 be operated vertical-1y, although this is not necessary. With the unit submerged in water, surrounding water passes through the tube 11 and cools the bulb 13 and adjacent parts. A 1000 watt bulb in a reflector having the size previously particularized will last as much as twenty hours or more. When used in saltwater, salt deposits on the bulb and on the inside of tube 11. Both can be easily cleaned in any convenient manner because the bulb is'easily removed; and can be readily replaced, if desirable. Thus, it can be seen that the applicants structure provides means for adequately cooling the bulb 13 with the water in which the light unit is used, while at the same time providing means for preventing entrance of the water into the reflector area, thereby preventing possible corrosion and/or fouling of the reflector area. Further, as previously pointed out, the device is-provided with means for ofisetting extreme pressure on the outer face of the trans- 4 parent front cover plate or lens 9. Still further, the device is'provided with means whereby the bulb 13 and electric leads 15 and 17 connected thereto may be removed from the light unit without necessitating contact with or exposure of the reflector surface.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be. practiced otherwise than as specifically described.

What is claimed is:

1. A light unit adapted for use under water, comprising an outer casing member having a wall means providing a concave reflector'within said member, said casing member having a bore extending through said wall means and intersecting the surface of the reflector adjacent the rear of the surface, a light-pervious open ended tube in said bore and having an outer diameter substantially equal to the diameter of the bore, said tube extending through and intersecting part of said surface, a high intensity elongated electric bulb within said tube, said bulb having end terminals, and connectors to each of said terminals extending therefrom to outside said wall means.

2. A light unit as set forth in claim 1 but further characterized by protecting means around said connectors watertightly sealing the connecion between said connectors andterminals.

3. A light unit adapted for use under water, comprising a casing member having wall means providing a concave reflector surface within said member, said member having a pair of bores therein, said bores extending through and inwardly of the respective sides of said member, said bores intersecting said reflector surface at opposite sides thereof, a light-pervious tubular means in said bores, said tubular means extending across the rear of the reflector surface; an electric bulb and the electric leads therefor within said tubular means, said tubular means being unobstructed and open at its opposite ends, whereby a bulb cooling fluid may flow therethrough by convection.

4. A light unit as set forth in claim 2, wherein said connectors are diametrically smaller than the inside of said bore, the bore being otherwise unobstructed.

5. A light unit adapted for use under water, as set forth in claim 3, wherein that portion of the casing member opposite the focal point of reflector surface is provided with a light emitting opening, a light-pervious plate or lens that extends across said opening, and means, including a gasket, sealing said plate to said casing member thereby preventing entry of water into said reflector area through said opening.

6. A light unit adapted for use under water, as set forth in claim 3, but further comprising means for providing a watertight seal in the space between the outer Wall of the tubular member and the adjoining wall of the respective bores, thereby preventing entry of the water that surrounds the unit into the reflector area through said space.

7. A light unit adapted for use underwater, comprising 'a casing member having a concave reflector surface within said member, said member having a pair of bores therein, said bores extending through and inwardly of the respective sides of said member, each bore intersecting 'said reflector surface at opposite sides thereof, a transparent tubular means' in said bores, said tubular means extending across the rear of the reflector surface; said tubular means being adapted to removably receive an elongated end-connection electric bulb and the electric leads therefor, said tubular means being openat its respective endsto the waterint o which the unit is adapted to be submerged, thereby providing ,means for cooling the bulb, a light emitting opening in said.unit opposite the transparent tubular means, a light-pervious plate'or lens removably attached -to said unit across said opening, a waterproof gasket interposedbetween the peripheral the tubular means and the adjoining wall of the respective bores, said seal adapted to prevent the passage of water between said outer wall and the adjoining wall of the bores and thus into the reflector.

8. A light as set forth in claim 7, wherein the unit is provided with a second closeable opening communicating with the reflector area, whereby clear water may be admitted into, and held within, the reflector area.

UNITED STATES PATENTS Everson Jan. 13, Lorenz J an. 31, Smith Sept. 24, Boerstler Apr. 12, Noel Sept. 8, Ekleberry May 13,

FOREIGN PATENTS Great Britain Dec. 1, Great Britain Nov. 8, 

